Re: [PATCH] pinctrl: renesas: Allow the compiler to optimize away sh_pfc_pm

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	 linux-renesas-soc@vger.kernel.org, linux-gpio@vger.kernel.org,
	 Paul Cercueil <paul@crapouillou.net>
Subject: Re: [PATCH] pinctrl: renesas: Allow the compiler to optimize away sh_pfc_pm
Date: Wed, 21 Feb 2024 14:37:21 +0100	[thread overview]
Message-ID: <CAMuHMdWA-q+O3hg=1KfsF5yZqr8x=Pf7ofT27s6nv1u+1TEO_w@mail.gmail.com> (raw)
In-Reply-To: <ZdX4SFXv53QyF49N@smile.fi.intel.com>

Hi Andy,

Cc Paul

On Wed, Feb 21, 2024 at 2:19 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
> On Wed, Feb 21, 2024 at 12:13:59PM +0100, Geert Uytterhoeven wrote:
> > The conversion to DEFINE_NOIRQ_DEV_PM_OPS() lost the ability of the
> > compiler to optimize away the struct dev_pm_ops object when it is not
> > needed.
> >
> > Fix this by replacing the use of pm_sleep_ptr() by a custom wrapper.
> >
> > Fixes: 727eb02eb753375e ("pinctrl: renesas: Switch to use DEFINE_NOIRQ_DEV_PM_OPS() helper")
>
> Is this a new requirement (I mean more than 12 digits of SHA)?

Nah, better safe than sorry, as 12 is becoming a bit small.
(Yes, I have to rework/resubmit patches related to that)

> > ---
> > To be queued in renesas-pinctrl for v6.9.
> >
> > Alternatively, one could add a unified definition:
> >
> >     #define pm_psci_sleep_ptr(_ptr)        PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP) && \
> >                                         IS_ENABLED(CONFIG_ARM_PSCI_FW), (_ptr))
> >
> > Since there are already separate sections for CONFIG_ARM_PSCI_FW enabled
> > vs. disabled, I split in two and simplified the definition.
>
> I'm fine with current approach, IIUC we discussed this that time and the
> 727eb02eb753 was not the first version (or I can be mistaken, I don't remember
> exact driver that the discussion was about during the DEFINE_NOIRQ_DEV_PM_OPS()
> conversions).

Thanks, I had forgotten about that discussion...

> FWIW,
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds